a(n) = 5*a(n-1) + 2*a(n-2), n > 1; a(0) = a(1) = 1.

Terms

a(0) =1a(1) =1a(2) =7a(3) =37a(4) =199a(5) =1069a(6) =5743a(7) =30853a(8) =165751a(9) =890461a(10) =4783807a(11) =25699957a(12) =138067399a(13) =741736909a(14) =3984819343a(15) =21407570533a(16) =115007491351a(17) =617852597821